1) The document discusses several theories of how languages have diffused and changed over time, including through conquest, the spread of agriculture, and human migration. 2) It describes Colin Renfrew's theory of a "superfamily" of languages tracing back over 10,000 years to ancient culture hearths in Anatolia. 3) The diffusion of Austronesian languages from China through the Pacific is discussed, including the emergence of three main dialects. 4) The Greenberg hypothesis proposing three main language families of indigenous Americas languages is outlined, though not all linguists agree. 5) The proliferation of early human languages is linked to lost contact between non-literate language groups, and the Middle Ages